Locking confirmation mechanism for a bone screw and plate assembly

ABSTRACT

Novel bone screw and plate assemblies including locking confirmation mechanisms are provided. In certain cases, a locking confirmation mechanism is operably attached to the plate, and comprises a toggling arm having an upper portion, a mid-portion and a lower portion. When a bone screw is positioned in a plate in an unlocked configuration, the locking confirmation mechanism assumes a first position. When the bone screw is positioned in the plate in a locked configuration, this causes the locking confirmation mechanism to pivot and assume a second position. The locking confirmation mechanism thus provides a convenient visual and/or tactile means to assess when the screw is in a locked configuration.

FIELD OF THE INVENTION

The present application generally relates to bone screw and plateassemblies, and in particular, to locking confirmation mechanisms forbone screw and plate assemblies.

BACKGROUND OF THE INVENTION

Bone screw and plate assemblies are commonly used in spinal surgery toassist in stabilizing bone members. Stabilizing bone plates can extendacross one or more vertebral bodies and can include one or more holesfor receiving bone screws. Once the bone screws are received in theplates, the bone screws are put into a locked configuration. To confirmthat the bone screws are received and/or locked in the plates, it ishelpful to provide a surgeon with some kind of visual, audible ortactile feedback.

Thus, there remains a need for improved confirmation mechanisms forconfirming that a bone screw is properly locked in a plate.

SUMMARY OF THE INVENTION

The present application relates to novel bone screw and plate assemblieshaving locking confirmation mechanisms. In some embodiments, a spinalassembly comprises a bone screw having a head portion and a threadedshaft; a plate having an aperture for receiving the bone screw, whereinthe bone screw is configured to be in an unlocked configuration and alocked configuration within the plate; and a locking mechanismoperatively attached to the plate, wherein the locking confirmationmechanism comprises a toggling arm having an upper portion, amid-portion and a lower portion, wherein the locking confirmationmechanism is configured to pivot about an axis when the bone screw movesfrom the unlocked configuration to the locked configuration therebyproviding visual confirmation of the bone screw in the lockedconfiguration.

In some embodiments, a spinal assembly comprises a bone screw having ahead portion and a shaft; a plate having an aperture for receiving thebone screw, wherein the bone screw is capable of being in an unlockedconfiguration and a locked configuration within the plate; and a lockingconfirmation mechanism operably attached to the plate, wherein thelocking confirmation mechanism comprises a pivoting arm having an upperportion, a mid-portion and a lower portion, wherein a section of theupper portion of the locking confirmation mechanism is positioned abovean uppermost portion of the plate when the screw is in an unlockedconfiguration and below an uppermost portion of the plate when the screwis in a locked configuration.

In some embodiments, a spinal assembly comprises a bone screw having ahead portion and a shaft; a plate having an aperture for receiving thebone screw, wherein the bone screw is capable of being in an unlockedconfiguration and a locked configuration within the plate; and a lockingconfirmation mechanism positioned in a slot formed in the plate, whereinthe locking confirmation mechanism is capable of pivoting such that whenthe bone screw is in an unlocked configuration, the locking confirmationmechanism obstructs a space formed in the slot, and wherein when thebone screw is in a locked configuration, the locking confirmationmechanism pivots thereby exposing the space formed in the slot.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-sectional view of a bone screw and plate assemblyhaving a locking confirmation mechanism in an open configurationaccording to some embodiments.

FIG. 1B is a cross-sectional view of the bone screw and plate assemblyof FIG. 1A with the locking confirmation mechanism in a partially closedconfiguration.

FIG. 1C is a cross-sectional view of the bone screw and plate assemblyof FIG. 1A with the locking confirmation mechanism in a closedconfiguration.

FIG. 2 is a cross-sectional view of a bone screw and plate assembly withthe bone screw in an angulated configuration according to someembodiments.

FIG. 3A is a top perspective view of a bone screw and plate assemblywith the bone screw in an angulated configuration according to someembodiments.

FIG. 3B is a top perspective view of a bone screw and plate assemblywith the bone screw in a straight configuration according to someembodiments.

FIG. 4A is a top view of a bone screw and plate assembly with a lockingconfirmation mechanism in an open configuration according to someembodiments.

FIG. 4B is a top view of a bone screw and plate assembly with a lockingconfirmation mechanism in a closed configuration according to someembodiments.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Detailed embodiments of the invention are disclosed herein; however, itis to be understood that the disclosed embodiments are merely exemplaryof the invention, which may be embodied in various forms. Therefore,specific structural and functional details disclosed herein are not tobe interpreted as limiting, but merely as a basis for the claims and asa representative basis for teaching one skilled in the art to variouslyemploy the present invention in virtually any appropriately detailedstructure.

The present application generally relates to bone screw and plateassemblies, and in particular, to locking confirmation mechanisms forbone screw and plate assemblies. The locking confirmation mechanismsdescribed herein provide a reliable and convenient mechanism for asurgeon to determine whether a bone screw is in a locked configurationwithin a plate. Advantageously, the locking confirmation mechanismsprovide multiple ways to determine whether a bone screw is in a lockedconfiguration within a plate. The locking confirmation mechanisms areeffective whether a bone screw is placed within a plate straight or atan angle.

FIG. 1A is a cross-sectional view of a bone screw and plate assemblyhaving a locking confirmation mechanism in an open configurationaccording to some embodiments. The bone screw and plate assembly 5 iscomprised of a bone screw 10, a plate 30 and a locking confirmationmechanism 50.

The bone screw 10 comprises a threaded shaft 16 that is operativelyattached to a head portion 18. The threads of the threaded shaft 16 canextend along the entire length of the threaded shaft, or along only aportion of the entire length of the threaded shaft. In some embodiments,the threads comprise single lead threads, while in other embodiments,the threads comprise dual lead threads.

As shown in the illustrated embodiment, the threaded shaft 16 can have atapering body. In some embodiments, the threaded shaft 16 assumes theform of a tapering body by having an internal shaft that is tapered,while in other embodiments, the threaded shaft 16 assumes the form of atapering body by having threads that are of different diameterssurrounding an internal shaft that is of a generally constant diameter.In other embodiments, the threaded shaft 16 has a generally constantdiameter and is not tapered.

The head portion 18 comprises a generally rounded or cylindrical memberthat can be seated within the plate 30. The head portion 18 includes atop engagement surface 22 that can receive one or more instruments fordriving the bone screw 10 into a bone member. In some embodiments, thehead portion 18 is capable of expansion and/or splaying. For example,the head portion 18 can be comprised of a flexible material and/or caninclude one or more features (e.g., slits) that allow for expansion ofthe head portion. Such expansion allows the head portion 18 to besecurely fixed within a hole or aperture of the plate 30. When the headportion 18 is securely fixed within a hole of the plate 30 (as shown inFIG. 1C), the bone screw 10 is in a locked configuration within theplate 30.

The bone screw 10 can be received in a hole or aperture 34 of a plate30. While the illustrated embodiment shows a single hole 34, the plate30 can include multiple holes, including two, three, four, five, six ormore. When the bone screw 10 is inserted and placed in a lockedconfiguration within the plate 30, the locking confirmation mechanism 50can serve as a visual indicator to inform a surgeon that the bone screw10 is in a locked configuration.

The locking confirmation mechanism 50, shown in different positions inFIGS. 1A-1C, comprises a toggling arm having an upper portion 52, amid-portion 54 and a lower portion 58 forming a “C” shape. In theillustrated embodiment, the upper portion 52 includes an angulatedsurface 57 that can accommodate different shaped bone screw heads. Inaddition, a rear protruding portion 56 extends from the back of thelower portion 58 of the C-shaped section of the locking confirmationmechanism 50. The rear protruding portion 56 advantageously helps thelocking confirmation mechanism 50 to be in an orientation that is readyfor use, as discussed in further detail below.

As shown in FIGS. 1A-1C, the locking confirmation mechanism 50 iscapable of moving, i.e. pivoting or translating about or on an axis froman “open” configuration (FIG. 1A) to a “closed” configuration (FIG. 1C).In the open configuration illustrated in FIG. 1A, the mid-portion 54 ofthe locking confirmation mechanism 50 is positioned such that a portionof the upper portion 52 of the locking confirmation mechanism 50 isproud and extends above an uppermost surface of the plate 30. As a bonescrew 10 is inserted downwardly into a hole 34 of the plate, the bonescrew 10 will contact a portion (e.g., the lower portion 58) of thelocking confirmation mechanism 50. This contact will begin to move thelocking confirmation mechanism 50 into the closed configuration as shownin FIGS. 1B and 1C. The following description of an exemplary operationof the locking confirmation mechanism 50 discusses a pivoting movementof the locking confirmation mechanism 50; however, other means ofmovement are contemplated including a translating movement and acombination translating and pivoting movement.

As the bone screw 10 is inserted further downwardly through the platehole 34, thereby moving closer to a locked configuration within theplate 30, the locking confirmation mechanism 50 continues to pivot. Asshown in FIG. 1B, which illustrates the locking confirmation mechanism50 in a partially-closed (or partially-opened) configuration midwaybetween the open and closed configurations, as the bone screw 10 isinserted further downward, the upper portion 52 of the lockingconfirmation mechanism 50 pivots towards the head 18 of the bone screw.In the partially-closed configuration in FIG. 1B, the lockingconfirmation mechanism 50 remains proud above the uppermost portion ofthe plate 30.

By the time the bone screw 10 is fully secured in a locked configurationin the plate 30, as shown in FIG. 1C, the mid-portion 54 of the lockingconfirmation mechanism 50 is in a substantially upwards or verticalposition. When the bone screw is in the locked configuration, thelocking confirmation mechanism 50 no longer pivots toward the bonescrew. As shown in FIG. 1C, a portion of the upper portion 52 of thelocking confirmation mechanism 50 can rest above or higher than the topsurface of the bone screw 10. However, in the closed configuration, theupper portion 52 of the locking confirmation mechanism 50 is no longerproud above the uppermost surface of the plate 30 (as shown in FIG. 1C),thereby advantageously providing a low-profile, visual means to assesswhether the bone screw 10 is in a locked configuration in the plate 30.

As discussed above, the locking confirmation mechanism 50 includes arear protruding portion 56. Advantageously, the rear protruding portion56 helps to ensure that the locking confirmation mechanism 50 is readilyavailable in a position for use. With the rear protruding portion 56,the locking confirmation mechanism 50 will not be overly pivoted in aforward direction (e.g., the upper portion 52 moving in the direction ofthe midline axis A-A), as the back surface of the rear protrudingportion 56 will contact a side wall of the aperture 34 of the plate 30before any over-pivoting occurs.

Advantageously, the locking confirmation mechanism 50 does not affecthow the bone screw 10 locks into the plate 30. In other words, thelocking confirmation mechanism 50 simply provides confirmation of whenthe bone screw 10 is locked in the plate 30, and does not affect thelocking operation itself. This advantageously allows the lockingconfirmation mechanism 50 to work with a variety of different bone screwand plate assemblies having a wide range of designs.

FIG. 2 is a cross-sectional view of a bone screw and plate assembly withthe bone screw in an angulated configuration according to someembodiments. As shown in this embodiment, the locking confirmationmechanism 50 works even when the bone screw 10 is angulated into alocked configuration. As the head portion 18 of the angulated bone screw10 contacts the lower portion 58 of the locking confirmation mechanism50, the locking confirmation mechanism 50 will pivot from an open toclosed position (similar as in FIGS. 1A-1C).

FIG. 3A is a top perspective view of a bone screw and plate assemblywith the bone screw in an angulated configuration according to someembodiments. From this view, it is clearly shown that the lockingconfirmation mechanism 50 is operable even when the bone screw isangulated through the plate. The upper portion 52 of the lockingconfirmation mechanism 50 can pivot in between the chamfered area 35 ofthe plate aperture and toward the head portion of the bone screw 10. Thelocking confirmation mechanism can move from an open to a closedconfiguration as shown in FIGS. 1A-1C.

FIG. 3B is a top perspective view of a bone screw and plate assemblywith the bone screw in a straight configuration according to someembodiments. The bone screw 10 is shown as having a longitudinal axisthat is substantially vertical through the aperture 34 of the plate 30.As in FIG. 3A, this view clearly shows the locking confirmationmechanism 50 operable when the bone screw is straight through the plate.

FIG. 4A is a top view of a bone screw and plate assembly with a lockingconfirmation mechanism in an open configuration according to someembodiments. From this view, it is apparent that the lockingconfirmation mechanism 50 is operably attached and comfortablypositioned within an opening or slot 38 formed in the plate 30. In FIG.4A, the bone screw 10 is not in a locked configuration. Accordingly, thelocking confirmation mechanism 50 is not pivoted in the direction of thehead portion of the bone screw 10 and therefore stands in an “open”configuration as in FIG. 1A. When the locking confirmation mechanism 50is an open configuration, the upper portion 52 of the lockingconfirmation mechanism 50 obstructs a space 60 formed in the slot 38(shown in FIG. 4B) that is visible when the locking confirmationmechanism 50 is pivoted into a “closed” configuration as in FIG. 1C.

FIG. 4B is a top view of a bone screw and plate assembly with a lockingconfirmation mechanism in a closed configuration according to someembodiments. In this embodiment, the bone screw 10 stands in a lockedconfiguration such that the locking confirmation mechanism 50 is fullypivoted in the direction of the head portion of the bone screw 10 andtherefore stands in a “closed” configuration as in FIG. 1C. When thelocking confirmation mechanism 50 is in a pivoted closed configuration,a space 60 is exposed in between the slot 38, thereby advantageouslyinforming a surgeon visually that the bone screw is locked in placewithin the plate. In addition to providing visual confirmation oflocking, a surgeon can also choose to insert an instrument through thespace 60 to confirm locking of the bone screw. In this way, the bonescrew and plate assembly also advantageously provides a tactile means ofproviding feedback of locking of the bone screw.

The bone screw and plate assemblies described herein thus include aconvenient locking confirmation mechanism that can provide visual and/ortactile feedback to confirm that a bone screw is locked within a plate.The locking confirmation mechanism does not affect how a screw locksinto a plate, thereby advantageously accommodating a number of differentbone screw and plate assembly designs.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the scope or spirit of the invention. Moreover,the improved spacer implants and related methods of use need not featureall of the objects, advantages, features and aspects discussed above.Thus, for example, those skilled in the art will recognize that theinvention can be embodied or carried out in a manner that achieves oroptimizes one advantage or a group of advantages as taught hereinwithout necessarily achieving other objects or advantages as may betaught or suggested herein. In addition, while a number of variations ofthe invention have been shown and described in detail, othermodifications and methods of use, which are within the scope of thisinvention, will be readily apparent to those of skill in the art basedupon this disclosure. It is contemplated that various combinations orsubcombinations of these specific features and aspects of embodimentsmay be made and still fall within the scope of the invention.Accordingly, it should be understood that various features and aspectsof the disclosed embodiments can be combined with or substituted for oneanother in order to form varying modes of the discussed spacer implants.Thus, it is intended that the present invention cover the modificationsand variations of this invention provided that they come within thescope of the appended claims or their equivalents.

What is claimed is:
 1. A spinal assembly comprising: a bone screw havinga head portion and a shaft; a plate having an aperture for receiving thebone screw, wherein the bone screw is capable of being in an unlockedconfiguration and a locked configuration within the plate; and a lockingconfirmation mechanism operably attached to the plate, wherein thelocking confirmation mechanism comprises a toggling arm having an upperportion, a mid-portion and a lower portion, wherein an uppermost surfaceof the locking confirmation mechanism as defined in the lockedconfiguration along a longitudinal axis of the aperture is positionedabove an uppermost portion of the plate when the bone screw is in theunlocked configuration and below the uppermost portion of the plate whenthe bone screw is in the locked configuration, wherein the lockingconfirmation mechanism is configured to fit in a slot in the plate,wherein when the bone screw is in the unlocked configuration, thelocking confirmation mechanism obstructs a space formed in the slot,wherein the locking confirmation mechanism pivots by contact of the headportion of the bone screw with a lower portion of the lockingconfirmation mechanism, thereby exposing the space formed in the slotwhen the bone screw is in the locked configuration.
 2. The spinalassembly of claim 1, wherein the upper portion, mid-portion and lowerportion form a C-shape.
 3. The spinal assembly of claim 1, wherein thelocking confirmation mechanism further comprises a rear protrudingportion that extends from a back portion of the locking confirmationmechanism.
 4. The spinal assembly of claim 3, wherein the rearprotruding portion is configured to contact an inner wall of the plateaperture to prevent over pivoting of the locking confirmation mechanism.5. A spinal assembly comprising: a bone screw having a head portion anda threaded shaft; a plate having an aperture for receiving the bonescrew, wherein the bone screw is moveable from an unlocked configurationto a locked configuration within the plate; and a locking confirmationmechanism operatively attached to the plate, wherein the lockingconfirmation mechanism comprises a toggling arm having an upper portion,a mid-portion and a lower portion, wherein the locking confirmationmechanism is configured to move about an axis when the bone screw movesfrom the unlocked configuration to the locked configuration therebyproviding visual confirmation that the bone screw is in the lockedconfiguration, wherein in the locked configuration, the lower portion ofthe locking confirmation mechanism is completely below an upper mostsurface of the head portion of the bone screw, wherein the lockingconfirmation mechanism is configured to fit in a slot in the plate,wherein when the bone screw is in the unlocked configuration, thelocking confirmation mechanism obstructs a space formed in the slot,wherein the locking confirmation mechanism pivots by contact of the headportion of the bone screw with the lower portion of the lockingconfirmation mechanism, thereby exposing the space formed in the slotwhen the bone screw is in the locked configuration.
 6. The spinalassembly of claim 5, wherein the upper portion, mid-portion and lowerportion of the locking confirmation mechanism form a C-shape.
 7. Thespinal assembly of claim 5, wherein the locking confirmation mechanismfurther comprises a rear protruding portion that extends from a back ofthe lower portion of the locking confirmation mechanism.
 8. The spinalassembly of claim 5, wherein the locking confirmation mechanismtranslates along the axis when the bone screw moves from the unlockedconfiguration to the locked configuration.
 9. A spinal assemblycomprising: a bone screw having a head portion and a shaft; a platehaving an aperture for receiving the bone screw, wherein the bone screwis capable of being in an unlocked configuration and a lockedconfiguration within the plate; and a locking confirmation mechanismpositioned in a slot formed in the plate, wherein the lockingconfirmation mechanism is capable of moving such that when the bonescrew is in the unlocked configuration, the locking confirmationmechanism obstructs a space formed in the slot, and wherein the lockingconfirmation mechanism pivots by contact of the head portion of the bonescrew with a lower portion of the locking confirmation mechanism therebyexposing the space formed in the slot when the bone screw is in thelocked configuration, wherein in the locked configuration, an uppermostsurface of the locking confirmation mechanism as defined in the lockedconfiguration along a longitudinal axis of the aperture is below anuppermost portion of the plate, wherein in the locked configuration, thelower portion of the locking confirmation mechanism is completely belowan upper most surface of the head portion of the bone screw.
 10. Thespinal assembly of claim 9, wherein the locking confirmation mechanismcomprises a toggle arm.
 11. The spinal assembly of claim 9, wherein thelocking confirmation mechanism comprises an upper portion, a mid-portionand the lower portion.
 12. The spinal assembly of claim 11, wherein theupper portion of the locking confirmation mechanism is configured toextend above the uppermost portion of the plate when the bone screw isin the unlocked configuration.
 13. The spinal assembly of claim 11,wherein the upper portion, mid-portion and lower portion form a C-shape.